Boiler



No'v. 15, 1938. J. w. PUTNAMQJR BOILER Filed Feb. 3, 1937 s sheets-sheet 1- Patented Nov. 15, 193s BOILER Joseph W. Putnam, Jr.,` Evanston, Il'l., assigner to Plibrico J ointless Firebrick Company, Chicago, Ill., a corporation of Illinois Application February 3, 1937, Serial No. 123,837

Claims.

This invention relates to water tube boilers, and has fto do withlthe baffling of such boilers for controlling the flow of the gases of combustion.

lVly invention is directed particularly to a novel 5 arrangement of baiiles for directing flow of the gases of combustion acrossthe water tubes in a manner conducive to ready flow of the gases-and `to rapid transfer of the heat from the gases to the'water tubesand the water contained therein.

Av A further object is so to arrange the baffles as to assure desirable heating of the downcorner tubes, while avoiding objectionable heating thereof such as would tend to interfere with proper delivery of feed water to the mud drum.

* Further objects and advantages will appear from` the detailed description.

vIn the drawings: Figure l is a sectional view from front to back through a boiler embodying my invention, parts 2b* beingJ broken away; i

Figure 2 is a'view similar to Figure 1 showing a modification of my invention; and

Figure 3 is aview similar to Figure l showing a second modification of my invention.

I` have illustrated my boiler as mounted in a suitable setting I comprising a furnace 2, firewall 3, and combustion chamber 4 above the furnace. The setting may be of any suitable or preferred construction. Steam and water drums 5; Iiand 1 are suitably mounted within setting I, at the` top thereof, and are connected by three banks of tubes to a lower mud drum 8 disposed inrear of the fire-wall 3. The front bank 9 of tubes connects the mud drum 8 to the front upper drum 1, and certainof the tubes of this bank,

designated 9a, are offset downwardly and forwardly to provide a slag screen. The middle bank of tubes, connecting the middle upper drum t to the muddrum 8, comprises 'a forward group I0 4()I anda rearward group Illa of tubes, separated by a space II of considerable cross-sectional area, this space being provided by offsetting forwardly the'mid-portions of several of the inner rows of tubesof the forward group I0 in the manner 475'l shown.- The rear bank of tubes I2 connects the rear upper drum 5 to the mud drum 8, and serves as downcomers for supplying feed water from K drum 5 tto the mud drum, it being understood that feedwater is delivered to drum 5 in a known `mann'erf.

portions, bysteam tubes I3, and the upper portions of drums `5 and 6 are connected by steam tubes I4 and I5. *The front and middle upper drums 1 and-I5 are connected, at their lower porslit tions, by watercirculating tubes I6, the space be-` Drums Ii and 1 are connected, at their upper y tween these two drums being closed by refractory I1 disposed above andadjacent tubes lli; Setting I I` is provided, at the rear and adjacent the top thereof, with an outlet I8, for the products of combustion, controlled by a damper I9. I k

A baffle 20 extends from mud drum 8 upward along the front bank 9 of tubes, at the back there? of, for the major portion of the length of this" bank. This bafe is provided, a shortdistance from its upper end, with a' projection 2t extend? 1`04 ing rearward therefrom across the space between the front bank and forwardgroup I0 ofi the tubes of the middle bank, this' projectionalso extending across the forward group of the tubes of the middle bank to thespace Il. extends from the rear of thermiddle upper drum downward along the rearV group of tubes/"Illa ofl the middle bank to a point an appreciable distance` below the inner end of extension 2|, and then downward and forward across the tubes of group 2b" Ict and space I I and the inner four rows of tubes of groupl ill, thence downward and` rearward across the four inner rows of tubesof group Ill` and space II and across the tubes of group Illa.

The lower portion of baffle 22 thus comprises 4two 251` angularly disposed elements 22a. and 22h togetherdeiining a substantially V-shaped rearwardly opening baffle element. A third baffle I 23" extends-from rear wall la of setting I to the rear bank of tubes and part w'ay across this latter 30 bank, substantially midway between the arms 22a, and 22h" defining the rearwardly openingl V- shaped baiiie element previously referred to. Preferably, an upper baffle 24' extends inwardly from wall lotto within a snort distance of the rear 35 bank I 2H ofV tubes.

The furnace may be of any suitable or preferred construction, and mayutiliZ-e solid', liquid, or gaseous fuel supplied thereto in an appropriate manner. The hot products of combustion flow 40 upwardly along the tubes of thefront bank, `then across the tubes of this bank between the upper end of baffle 20 and drum "I, thence `across the upper portionsof tubes of group lil andspace IIand across the upper portions of tubes of` 4451 group Illa, reversing their direction of flow in the latter group of tubes andv then flowing forward across space II and theV intermediate portions'of the tubesof group iintofthe space between the latter group of tubes and the baffle 5f0` y 2B', reversing their direction of flow in this space and thence flowing downward and rearward across the lower portion of the tubes of group IIT,` across space II, and then across theflower` portion ofthe tubes of group IIJa andof the'rear A second balile 223 f5" bank I2, passing thence upwardly and forwardly across the rear bank I2 of tubes and the tubes of group Illa, then reversing and passing upwardly and rearwardly across tubes Illa and the tubes of bank I2, then upwardly along the tubes of the latter bank, and thence to the outlet I8. The path of flow of the combustion gases is indicated by the arrows. It will be noted that the bailles cause the hot combustion gases to pass back and forth across the tubes a plurality of times, which is conducive to rapid and thorough transfer of heat from the hot gases to the tubes and the water therein. The gases of combustion do not pass across the tubes of the rear bank I2 until after they have passed across the tubes of the front and middle banks a plurality of times and have delivered a large portion of their heat to these tubes and the water therein, so that such gases are relatively cool when they rst pass across the rear bank of tubes. This is advantageous in that the combustion gases are used to advantage for heating to a desirable slight extent the water delivered by the tubes of the rear bank to the mud drum 8, while objectionable heating of these tubes, to such an extent as to tend to interfere with proper delivery of feed water to the mud drum, is prevented.

The bailies are so related to each other and to the drums and the banksof tubes that the net area-of the space between they upper end of baille 20 and drum 1 is more than the net area of the space between drum 6 and projection 2| oi' baillev 20, the net area of the latter space being less than the net area of the space between baille 22 and the inner end of projection 2I of baille 20. The net area of the space between the baille 20 and the rear end of projection 2I is greater than the net area of the space between projection 2| and element 22a of baille 22, and the net area of the space between baille 20 and the forward end of element 22a is less thanthe net area of the space between baille 22 and the rearward end of projection 2| but greater than the net area of the space between projection 2| and element 22a.

The net area of the space between the rearward end of element 22b and the rear wall la of setting I is less than the net area of the space between baille 20 and the forward end of element 22a, and is greater than the net area of the space between the forward end vof baille 23 and the rearward end of element 22a, the net area of the latter space being vgreater than the net area of the space between baille 22 and the forward end of baille 24. 'Ine bailles and associated parts thus define a passage for the combustion gases, which passage decreases in cross sectional area to the space between baille 22 and projection 2l, Where the area of the passage increases, there permitting expansion of the gases, the cross-sectional area of the passage, in general, then decreasing to the outlet opening. I8. I nd that forming the passage in this manner is advantageous in that flow ofthe gases is retarded somewhat, while maintaining adequate velocity of flow which, in conjunction with the expansion of the gasesV within the middle bank of tubes, is conducive to rapid and high transfer of heat from the combustion gases to the tubes and the water contained therein. y

In the modification illustrated in Figure 2, bafile 22e is provided at its lower end with a rearwardly opening baille element of approximately flattened V shape, defined by the arms 22d and 22e and element 22j connecting the forward` ends VThe setting may be of any suitable or preferred construction. Steam and water drums 34 and 35 are suitably mounted within setting 3i) at the top thereof, and ay submerged water drum 36 is mounted in the setting adjacent the upper portion of front wall 3013 thereof. The upper drums,l

34, 35 and 36 are connected by three banks of tubes to a lower mud drum 31 disposed in rear of the fire wall 32. The front bank 38 of tubes connects the mud drum 31 to the water drum 36. Drum 35 is connected to mud drum 31 by a middie bank 39 of tubes, and drum 34 is connected to the mud drum 31 by a rear bank 40 of tubes, the tubes of this latter bank serving as downcomers for supplying feed mud drum, it being understood that feed water is delivered to drum 34 in a known manner. Drums 35 and 36 are connected by a bank 4I of water tubes entering drum 35 at the lower portion thereof, and the upper portions of drums 34 and 35 are connected by rows of steam tubes 42 and 43. Setting 30 is provided, at the rear and adjacent the top thereof, with an outlet 44, for the products of combustion, controlled by a damper 45. Y

A baille 46 extends from mud drum 31 upward along the front bank 38 of tubes, at the back thereof, for the major portion of the length of this bank. This baille is provided, at its upper end, with a projection 41 extending rearward therefrom across the space between the front bank and middle bank of tubes, this projection also extending across the tubes of the middle bank. A second baille 48V extends from the bottom of the rear upper drum 34 downward along rear bank 48, at the back of the rst row of tubes of this bank, to a point an appreciable distance below the inner end of extension 41, then downward and forward acrossy the front row of tubes of bank 4i), space 49 between the banks 39 and 40 and the last three rows of tubes of bank 39, then downward a short distance between the third and fourth rows of tubes of bank 39, thence downward andY rearward across the last three rows of tubes of bank 39, the lower portion of space 49 and the rst or front row of tubes of rear bank 48. The lower portion of bafile 48 thus comprises two oppositely inclined arms 48a. and 48h connected, at their forward ends, by an element 48e dening, with arms 43a` and 48D, a

element of approxi- The forward portion rearwardly opening baille mately flattened V shape. of drum 34 is provided with a refractory covering 5I] extending from the roof of the setting to the upper end of baille 48. A third baille 5I extends from rear wall 39a of setting 30 tothe rear bank of tubes and across this latter bank to the forward row of tubes thereof, substantially midway between the arms 48a. and 48h defining the rearwardly opening bailleelernent of approximately attened V shape previously referred to. Preferably, an upper baille 52 extends inwardly from wall 30a to within a short distance of the rear bank 40 of tubes, and then upward a short distance along this bank. Y

'I'he hot productsof combustion iiow upward water from drum 34 to theA along the tubes of the front bank, then across the 76.

. The gases of combustion do not pass i middlebank 3B; Abetween baffle tubes of this fbank'fbetween the upper end of bafflel`46-anddrurn36, andlthen across the tubes ofthe middle bank`39 between baffle41 and drum -into 'space 4S. The products of combustion then pass downward lin space 49, in fpartalong bafe`48 and the upper portions of the tubes of the -front `rowfof Arear. bank 40, reversing their direction of `flowand passing across the tubes of 41 and arm 48a, of baiile 48', into space 53 between baflie 45 and thel middle bank 39 of tubes. From space 53 tlieproducts-of combustion pass downward across the lower yportions of the tubes of vthe middle bank 39, vbetween arm 48h ofbafe 48 and mud drum "-31, across space `4%), andthe lower portions of the tubes'of'the rear bank MLA The products of corribustion then lpass in reverse direction across theltubes of Abank `4l), between arm 4th of `baille 48` and baiiie `5|`, `into space 49 between arms 48a and 43h of baffle 48, there reversing their direction of flow and passing again across the tubes of bank 4G between baflie 5I and arm 48a of baffle 48, thence flowing upward along the tubes of bank 40 between baflies 48 and 52, and thence tothe outlet 44. The path of ow of the combustion gases is indicated by the arrows. These gases are caused to pass back and forth across the banks. of tubes a pluralityT of times, due to the bafflearrangement, which is conducive to rapid and thorough transfer of heat from the hot gases to the tubes and the water therein. across the tubes of the rear bank 40 until after they have `the space between drum passed across the tubes of the front and the middle banks a number of times and have delivered a large portion of their heat to these tubes and the water therein, so that such gases are relatively cool when they first pass across the rear bank of tubes. The water in this rear bank of tubes is thus heated to a desirable slight extent, While avoiding objectionable heating thereof such as to tend to interfere with proper delivery of feed water to the mud drum.

The baffles are so relatedto each other and to the drums and the banks of tubes as to define a passage of flow for the combustion gases which, as in Figure 1, in general decreases in net crossarea from the combustion space 33 to the outlet 44, it being noted, however, that the net area of the space between the inner end of baffle element 41 and bafe 48 is greater than the net area of 35 and baffle element 41 and the space between baffle element 41 and arm 48a of bafile 48. In this manner, the passage for the combustion gases is provided, between the inlet and the outlet thereof, with an area or space of increased net area relative to the immediately adjacent preceding andsucceeding spaces, permitting of desirablev expansion of the gases without objectionably interfering with or retarding flow thereof. The arrangement of the baflies and the passage for the flow of the combustion gases will be clear from Figure 3 and need not be described in greater detail.

It will be understood that, in practice, changes in construction and arrangement of parts of my invention may be resorted to without departing from the field and scope of the same, and I intend to include all such variations, as fall within the scope of the appended claims, in this application, 'in which the preferred form only of my invention is disclosed.

i What I claims is:

1. In combination in a water tube boiler ofthe character described, a setting defining a furnace and lprovided withvawrear outlet `for products of combustion, three `upper'drums and a lower mud drum, banks of tubes connecting said upper drums Vto said mud drum, the forward bank of tubes 'extending over said furnace, aibaiiie extending fromsaid mud drum' along said forward bank of 'tubesfor the lmajor portion `of the length thereof andthence rearward across the middle bank offtubes, a secondbafile extending from an upperdrumldownward adjacent the front of the rear `bank of tubes beyond the rearward extension of `said rst bailie and then downward and forward and downward and rearward across `said middle bank, defining a substantially V-shaped rearwardly opening baiiie element, and a third baffle extending from the rear wall of said setting across the rear bank of tubes between the arms of said substantially V-shaped element.

12. In combination in a water tube boiler of the character described, a setting defining a furnace and provided adjacent its top with a rear outlet for the products of combustion, three upper steam and water drums and a lower mud drum, banks of tubes connecting said upper drums to said mud drum, the forward bank of tubes extending over said furnace, a baffle extending from the mud drum along said forward bank of tubes for the major portion of the length thereof and thence rearward part way across the middle bank of tubes, a second bafiie extending from the middle upper drum downward along the middle bank of tubes beyond the rearward extension of said first baille and then downward and forward and downward and rearward across said middle bank, defining a substantially V-shaped rearwardly opening baffle element, and a third baffle extending from the rear wall of said setting across the rear bank of tubes between the arms of said V-shaped element.

Y 3. In combination in a water tube boiler of the character described, a setting defining a furnace and provided adjacent its top with a rear outlet for the products of combustion, three upper steam and water drums and a lower mud drum, banks of tubes connecting said upper drums to said mud drum, the forward bank of tubes extending over said furnace, a baille extending from the mud drum along said forward bank of tubes at the back and for the major portion of the length thereof and thence part way,across the middle bank of tubes, a second baffle extending from the middle upper drum downward along the middle bank of tubes at the back thereof in spaced relation to the rearward extension of said first baiile and then downward and forward and downward and rearward across said middle bank, dening a substantially V-shaped rearwardly opening baffle element, and a third baille extending from the rear wall of said setting across the rear bank of tubes between the arms of said V-shaped element.

4. In combination in a water tube boiler of the character described, a setting defining a furnace and provided adjacent its top `with a rear outlet for the products of combustion, three upper steam and water drums and a lower mud drum, banks of tubes connecting said upper drums to said mud drum, the forward bank of tubesl extending over said furnace and the middle bank of tubes comprising a forward group and a rearward group with a space of considerable cross-sectional area therebetween, a baffle extending from the mud drum along said forward bank at the back and for the major portion of the length thereof and thence rearward across the forward group of tubes of the middle bank, a second bale drums to said mud drum, the forward bank of extending from the middle upper drum downward tubes extending over said furnace, a baffle extendforward group of tubes to and across said rearsectional area, a second bale extending from the ie ward group of tubes, dening a substantially rear upper drum downward along the rear bank combustion, three upper drums and a lower mud between the arms of said V-shaped element. 

